Horizon Screening Options

Comprehensive
screening options

Comprehensive
screening options

Comprehensive
screening options

Comprehensive
screening options

Disease List:

3 6 A B C D E F G H I J K L M N O P R S T U V W Z

CRB1-Related Retinal Dystrophies

  • Horizon 274

What are CRB1-Related Retinal Dystrophies?

CRB1-Related Retinal Dystrophies are a group of autosomal recessive inherited disorders that include Leber Congenital Amaurosis-8 and Retinitis Pigmentosa-12.  Leber Congenital Amaurosis-8 causes severe vision loss that is either present at birth or begins in early childhood and progresses to complete vision loss over time.  Other symptoms of Leber Congenital Amaurosis-8 may include light sensitivity (photophobia), abnormal eye movements (nystagmus), cataracts, and thinning of the cornea (covering of the eye).  Retinitis Pigmentosa-12 causes loss of vision that often starts in childhood and worsens over time but does not cause other symptoms. Currently there is no cure for the CRB1-Related Retinal Dystrophies.

What causes CRB1-Related Retinal Dystrophies?

The CRB1-Related Retinal Dystrophies are caused by a gene change, or mutation, in both copies of the CRB1 gene pair.  These mutations cause the genes to not work properly or not work at all. The CRB1 genes make a protein that is important for the normal development of light-sensing cells in the retina of the eye called photoreceptors. When both copies of the CRB1 gene do not work correctly, vision loss occurs. 

Creatine Transporter Defect (Cerebral Creatine Deficiency Syndrome 1, X-Linked)

  • Horizon 274

What is Creatine Transporter Defect (Cerebral Creatine Deficiency Syndrome 1, X-Linked)?

Creatine Transporter Defect (also known as Cerebral Creatine Deficiency Syndrome 1 or X-linked Creatine Deficiency) is an X-linked disorder that affects mainly males and causes intellectual disability, behavior problems, seizures, and muscle weakness. Affected males have symptoms beginning in infancy that include small head size, development and growth delays, characteristic facial features, digestive problems, and poor muscle tone. Currently there is no cure for this condition and treatment is based on symptoms.

What causes Creatine Transporter Defect?

Creatine Transporter Defect is caused by a change, or mutation, in the SLC6A8 gene. This mutation causes the gene to not work properly or not work at all. People with this disorder do not make a protein needed to allow creatine, a substance that is required for the body to store and use energy, into a cell. Parts of the body that require a lot of energy, such as the brain, are affected when there is not enough creatine available.  

Cystic Fibrosis

  • Horizon 4
  • Horizon 14
  • Horizon 27
  • Horizon 106
  • Horizon 274

What is Cystic Fibrosis?

Cystic Fibrosis is an autosomal recessive disorder that affects many different areas of the body including the lungs, digestive system, and fertility.  Cystic Fibrosis does not affect intelligence.  Signs and symptoms of Cystic Fibrosis start in early childhood and include delayed growth caused by problems in digestion and repeated lung infections that lead to permanent lung damage. Children and adults with Cystic Fibrosis usually have frequent hospitalizations because of lung infections.  Over time, complications of Cystic Fibrosis can lead to lung transplants and early death.  There are treatments for Cystic Fibrosis that can lessen the severity of the symptoms; however, there is currently no cure.  

What causes Cystic Fibrosis?

Cystic Fibrosis is caused by a change, or mutation, in both copies of the CFTR gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, mucus and other body fluids become thick and sticky. This causes problems with how the lungs, digestive system, and other body systems function and leads to the symptoms described above.   

Although most CFTR gene mutations cause classic CF, there are some specific CFTR mutations that cause less severe symptoms, and some only affect male fertility. 

Cystinosis

  • Horizon 106
  • Horizon 274

What is Cystinosis?

Cystinosis is an autosomal recessive disorder that causes the amino acid cysteine, one of the building blocks of protein, to build up in cells of the body.  The excess cysteine forms crystals which can damage tissues and organs in the body. Damage to the kidneys and eyes occurs most often, but damage to the muscles, thyroid, pancreas, and testes may also occur. There are three forms of Cystinosis that have symptoms which range from mild to severe. The most severe form, called Nephropathic Cystinosis, starts shortly after birth. Symptoms include poor growth and a kidney disorder that leads to loss of minerals and nutrients in the urine. Cysteine crystals also build up in the eyes, causing sensitivity to light, eye pain, and vision loss. Symptoms also include loss of muscle mass, difficulty swallowing, diabetes, thyroid and nervous system problems. The childhood-onset form starts later but shows the same type of symptoms. There is also a milder form that causes eye problems but usually does not cause kidney damage. Medical treatment can lessen or delay some of symptoms of Cystinosis.  Without treatment, children with Cystinosis may develop kidney failure by age 10 and need a kidney transplant. 

What causes Cystinosis?

Cystinosis is caused by a gene change, or mutation, in both copies of the CTNS gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it leads to the symptoms described above.

D-Bifunctional Protein Deficiency

  • Horizon 274

What is D-Bifunctional Protein Deficiency?

D-Bifunctional Protein Deficiency is an autosomal recessive disorder in which the body cannot break down certain building blocks of fat called ‘fatty acids’.  This leads to the buildup of fatty acids in the blood and organs that then cause damage to many parts of the body, especially the brain and nervous system.  Signs and symptoms begin in infancy and include large head size, distinct facial features, feeding problems, poor muscle tone, vision and hearing loss, liver and kidney disease, seizures, severe developmental delay, and bone abnormalities.  There is no cure for this disorder and death usually occurs before two years of age.  Rarely, a child with this condition may start having symptoms at a later age leading to loss of skills and death later in childhood.

Very rarely, mutations in the same gene cause a different disorder called Perrault Syndrome.  Symptoms of Perrault Syndrome include hearing loss starting at birth or early childhood that worsens over time and, in females, missing or non-working ovaries with infertility. Some people with this condition also have learning difficulties, problems with coordination and walking, and loss of sensation in the arms and legs. 

What causes D-Bifunctional Protein Deficiency?

D-Bifunctional Protein Deficiency is caused by a gene change, or mutation, in both copies of the HSD17B4 gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it leads to the symptoms described above.

Deafness, Autosomal Recessive 77

  • Horizon 106
  • Horizon 274

What is Deafness, Autosomal Recessive 77?

Deafness, Autosomal Recessive 77 is an autosomal recessive disorder that affects hearing.  Affected individuals usually develop hearing loss beginning in childhood.  The hearing loss worsens with age.  This condition does not cause other health problems.

What causes Deafness, Autosomal Recessive 77?

Deafness, Autosomal Recessive 77 is caused by a change, or mutation, in both copies of the LOXHD1 gene pair.  These mutations cause the genes to not work properly or not work at all.  Normal function of the LOXHD1 genes is important for hearing.  When both copies of the LOXHD1 gene do not work correctly, progressive hearing loss occurs. 

Duchenne/Becker Muscular Dystrophy

  • Horizon 4
  • Horizon 14
  • Horizon 27
  • Horizon 106
  • Horizon 274

What is Duchenne/Becker Muscular Dystrophy?

Duchenne and Becker Muscular Dystrophy are two forms of an X-linked inherited disorder that causes progressive breakdown and weakness of skeletal muscle. In Duchenne Muscular Dystrophy, the muscle weakness usually begins around 3 to 5 years of age and worsens over time.  By the teenage years, the muscle degeneration and weakness also starts to involve the muscles of the lungs and heart. In Becker Muscular Dystrophy, the signs and symptoms are milder and begin later in childhood. For both conditions, it is more common for boys to be affected than girls. Children and adults with Duchenne/Becker Muscular Dystrophy need physical and occupational therapy and lifelong medical treatment. Most boys with Duchenne Muscular Dystrophy will need a wheelchair by their mid to late teenage years; boys with Becker Muscular Dystrophy are often in their late teens or early adulthood before they need a wheelchair.  A variable degree of intellectual disability may occur and is more common in children with Duchenne than in children with Becker.  Presently there is no cure for Duchenne/Becker Muscular Dystrophy. With current medical treatments, survival is common into the 20s and 30s with Duchenne Muscular Dystrophy and into the 40s with Becker Muscular Dystrophy.  About 1 in every 3500 males is born with Duchenne Muscular Dystrophy and about 1 in every 18,500 boys is born with Becker Muscular Dystrophy.

What causes Duchenne/Becker Muscular Dystrophy?

Duchenne/Becker Muscular Dystrophy is caused by a change, or mutation, in the DMD gene.  This mutation causes the gene to not work properly or not work at all.  When this gene does not work correctly, it leads to a lack of dystrophin, a protein normally found in muscle cells. Muscle cells in the skeleton and heart that don’t have enough dystrophin gradually stop working, leading to the symptoms described above. It is sometimes but not always possible to tell just by the mutation whether a boy will have the Duchenne or Becker form of this condition. 

Dyskeratosis Congenita, RTEL1-Related

  • Horizon 106
  • Horizon 274

What is Dyskeratosis Congenita, RTEL1-Related?

Dyskeratosis Congenita, RTEL1-Related (also called Dyskeratosis Congenita, Autosomal Recessive 5) is an autosomal recessive disorder that affects mainly the skin, bone marrow, and immune system. Signs and symptoms vary from person to person but often include immune system problems, increased pigment in the skin, abnormalities of the nails, and white patches on the insides of the mouth called oral leukoplakia. Other symptoms may include developmental delay, anemia, bone marrow failure, and heart, lung, and liver complications. People with this condition are at increased risk for developing leukemia or other cancers.

What causes Dyskeratosis Congenita, RTEL1-Related?

Dyskeratosis Congenita, RTEL1-Related is caused by a gene change, or mutation in both copies of the RTEL1 gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of the RTEL1 gene do not work correctly, it leads to the symptoms described above.

Very rarely, a mutation in the same gene causes a related disorder that is inherited in an autosomal dominant manner, either Dyskeratosis Congenita, Autosomal Dominant 4 (DKCA4) or Pulmonary Fibrosis and/or Bone Marrow Failure Telomere-Related 3. Dyskeratosis Congenita, Autosomal Dominant 4 causes progressive bone marrow failure, nail abnormalities, and oral leukoplakia and sometimes includes premature graying of the hair, anemia, low platelets, osteoporosis, and fibrosis (replacement of normal tissue with fibrous scar tissue) of the lungs and liver. Lifespan is sometimes shortened due to bone marrow failure, lung damage, or cancer. Pulmonary Fibrosis and/or Bone Marrow Failure, Telomere-Related 3 causes fibrosis of the lungs and sometimes also includes bone marrow failure, fibrosis of the liver and increased risk for cancer. 

Dystrophic Epidermolysis Bullosa, COL7A1-Related

  • Horizon 274

What is Dystrophic Epidermolysis Bullosa, COL7A1-Related?

Dystrophic Epidermolysis Bullosa, COL7A1-Related is an inherited disorder that has two forms, autosomal recessive and autosomal dominant. The autosomal recessive form causes severe repeated blistering of the skin and mucous membranes. Blisters are usually present at birth or start forming shortly after birth. Blisters may form anywhere on the body but are found most often on the hands and feet. Blisters may also occur on internal organs, such as the esophagus, stomach, and respiratory tract. When the blisters heal, they form scars that can cause problems with hand and limb movements, eating and digesting food, and vision. Infection, malnutrition, and dehydration may cause death in some infants. Children who survive are at increased risk of developing a type of skin cancer called squamous cell carcinoma. Carriers of the autosomal recessive form of this disorder are not expected to have symptoms. The other form of Dystrophic Epidermolysis Bullosa, COL7A1-Related is inherited in an autosomal dominant manner and is typically milder. In the autosomal dominant form, nails may be absent or small. Blistering may be limited to the hands, feet, knees, and elbows, and may improve with age, although scars may be permanent. Growth is typically normal and risk of squamous cell cancer may be increased slightly or not at all.

What causes Dystrophic Epidermolysis Bullosa, COL7A1-Related?

Dystrophic Epidermolysis Bullosa, COL7A1-Related with autosomal recessive inheritance is caused by a gene change, or mutation, in both copies of the COL7A1 gene. These mutations cause the genes to not work properly or not work at all. When both copies of the COL7A1 gene pair are not working correctly, it leads to the symptoms of the autosomal recessive form described above.

Mutations in the same gene (COL7A1) sometimes cause a milder form of the condition inherited in an autosomal dominant manner. Individuals with a mutation in one COL7A1 gene are affected and have symptoms of Dystrophic Epidermolysis Bullosa, COL7A1-Related although they are usually milder than the autosomal recessive form

Ehlers-Danlos Syndrome, Type VIIC

  • Horizon 106
  • Horizon 274

What is Ehlers-Danlos Syndrome, Type VIIC?

Ehlers-Danlos Syndrome, Type VIIC is an autosomal recessive disorder of connective tissue which causes the skin to be extremely fragile and excessive bruising is common. Most people with Ehlers-Danlos Syndrome, Type VIIC have changes in their facial features that include puffy eye lids, full lips, small chin, and blue coloring of the whites of the eyes (blue sclera).  People with this condition also have short stature and small hands and feet with multiple skin folds around the fingers and ankles. Extreme flexibility of the joints (hypermobility) and skin sagging are common and worsen with age.  The skin also becomes more fragile with age and frequent skin infections may occur, which are difficult to treat. These infections can sometimes lead to early death.

What causes Ehlers-Danlos Syndrome, Type VIIC?

Ehlers-Danlos Syndrome, Type VIIC is caused by a gene change, or mutation, in both copies of the ADAMTS2 gene.  These mutations cause the genes to not work properly or not work at all.  When both copies of the ADAMTS2 gene do not work correctly, it leads to the symptoms described above.

Ellis-van Creveld Syndrome, EVC-Related

  • Horizon 274

What is Ellis-van Creveld Syndrome, EVC-Related?

Ellis-van Creveld (EVC) Syndrome, EVC-Related is an autosomal recessive disorder that causes short stature, changes in the skeleton, and other birth defects. Signs and symptoms begin before birth. Bones develop abnormally and affected infants have short forearms and lower legs, narrow chest with short ribs, and extra fingers and toes. Other symptoms that may occur include cleft lip, abnormal development of the teeth, heart defects, male genital abnormalities, underdeveloped finger- and toenails, and intellectual disability.

What causes Ellis-van Creveld Syndrome, EVC-Related?

Ellis-van Creveld Syndrome, EVC-Related is caused by a change, or mutation, in both copies of the EVC gene. These mutations cause the genes to not work properly or not work at all. Normal function of the EVC gene is important for forming the bones and other parts of the body. When both copies of the EVC gene pair do not work correctly, it results in the symptoms described above.

Very rarely, a mutation in the same gene that causes Ellis-van Creveld Syndrome, EVC-Related instead causes a related autosomal dominant condition called Weyers Acrofacial Dysostosis that affects the bones, teeth, and nails. Symptoms of this condition are milder than Ellis-van Creveld Syndrome, EVC-Related and often include missing or small teeth, misshaped jaw bone, small or unusually shaped nails, and short stature. 

Emery-Dreifuss Muscular Dystrophy 1, X-Linked

  • Horizon 274

What is Emery-Dreifuss Muscular Dystrophy 1, X-Linked?

Emery-Dreifuss Muscular Dystrophy 1, X-Linked is an X-linked inherited disorder that affects mainly boys. It causes weakness in the muscles used for movement (skeletal muscles) and the heart muscle. Muscle weakness starts in the upper arms and lower legs and worsens to involve the muscles in the shoulders and hips. Stiff joints (contractures) occur over time and limit the movement of the elbows, ankles, and neck. Signs of Emery-Dreifuss Muscular Dystrophy 1, X-Linked usually appear by age 10. Almost all people with this disorder have heart problems by adulthood. If untreated, this can lead to an unusually slow heartbeat, fainting, and an increased risk of stroke and sudden death.  Currently there is no cure for Emery-Dreifuss Muscular Dystrophy 1, X-Linked and treatment is based on symptoms.  Some female carriers have heart problems, and, while rarer, some have other symptoms such as mild to moderate muscle weakness.

What causes Emery-Dreifuss Muscular Dystrophy 1, X-Linked?

Emery-Dreifuss Muscular Dystrophy 1, X-Linked is caused by a change, or mutation, in the EMD gene. This mutation causes the gene to not work properly or not work at all. When the EMD gene is not working correctly in a male, it leads to the symptoms described above.

Enhanced S-Cone Syndrome

  • Horizon 106
  • Horizon 274

What is Enhanced S-Cone Syndrome?

Enhanced S-Cone Syndrome (also known as Goldmann-Favre Syndrome) is an autosomal recessive eye disorder that causes vision loss, night blindness, cataracts, increased sensitivity to blue light, and specific findings on eye examination. Signs and symptoms usually begin in childhood and are caused by breakdown of the retina (the light sensitive tissue in the back of the eye). The symptoms progress over time and vision worsens with age. Currently there is no cure for this disorder and treatment is based on symptoms.

What causes Enhanced S-Cone Syndrome?

Enhanced S-Cone Syndrome is caused by a gene change, or mutation, in both copies of the NR2E3 gene pair. These mutations cause the genes to not work properly or not work at all. Normal function of the NR2E3 gene pair is important for the health of the retina in the eye. When both copies of the NR2E3 gene do not work correctly, it leads to the symptoms described above. 

Ethylmalonic Encephalopathy

  • Horizon 274

What is Ethylmalonic Encephalopathy?

Ethylmalonic Encephalopathy is an autosomal recessive disorder that reduces the body’s ability to make energy. The signs and symptoms usually start shortly after birth. Children with this disorder typically have developmental delay, seizures, weak muscle tone (hypotonia), chronic diarrhea, reduced oxygen to the hands and feet causing bluish-white coloring, and problems with the blood vessels that cause a red rash. Children with this disorder usually do not live past 10 years of age.  Special dietary treatment and supplements may help delay the progression of the symptoms.

What causes Ethylmalonic Encephalopathy?

Ethylmalonic Encephalopathy is caused by a change, or mutation, in both copies of the ETHE1 gene pair.  These mutations cause the genes to not work properly or not work at all.  The function of the ETHE1 genes is to help make energy for the cells of the body.  When both copies of this gene are not working correctly, it leads to the symptoms described above.

Fabry Disease

  • Horizon 274

What is Fabry Disease?

Fabry Disease is an X-linked inherited disorder that causes a buildup of a certain type of fat in the cells of the body.  Affected males usually have signs and symptoms beginning in childhood.  Fabry Disease causes pain episodes, often of the hands and feet; red spots on the skin (angiokeratomas); lack of sweating; cloudiness of the corneas of the eyes (corneal opacity); hearing loss; slow weight gain; digestive problems and pain; progressive kidney failure; and heart disease (arrhythmia). The severity of Fabry Disease varies from person to person, with some males having mild symptoms and others having more severe disease. Over time, the symptoms of Fabry Disease can include kidney failure, stroke, and heart attacks, all of which can be life-threatening. Some females who are carriers for Fabry Disease develop some symptoms although they are usually milder.  Life-long treatment with special diet and enzyme replacement therapy is available for Fabry Disease.   

What causes Fabry Disease?

Fabry Disease is caused by a change, or mutation, in the GLA gene.  This mutation causes the gene to not work properly or not work at all.  People with Fabry do not make an enzyme that normally breaks down certain fats in the body. When these fats are not broken down and removed from the body, they build up and lead to the symptoms described above. 

Factor IX Deficiency

  • Horizon 274

What is Factor IX Deficiency?

Factor IX Deficiency, also known as Hemophilia B or Christmas disease, is an X-linked inherited bleeding disorder that affects boys more often than girls.  Factor IX is a protein that helps to clot blood after injury.  If the body does not make enough normal Factor IX, it causes longer than average bleeding times, especially following surgery, injury or trauma, and tooth extractions. The symptoms of Factor IX Deficiency can be mild, moderate, or severe and vary from person to person.  People with severe Factor IX Deficiency have symptoms that start in early childhood and have episodes of uncontrolled bleeding in the brain, joints, muscles, or other organs, even without injury.  Nosebleeds, easy bruising and blood in the urine are also common.  People with moderate Factor IX Deficiency usually show symptoms by the age of 5 or 6 and often have prolonged bleeding after minor injuries, surgeries, or tooth extraction.  Mild Factor IX Deficiency causes bleeding problems after surgery and tooth extraction but usually not with minor injury and may not be recognized until later in life.  Children with Factor IX Deficiency are likely to need lifelong medical care.  Treatment for Factor IX Deficiency often includes infusions of Factor IX to help restore normal blood clotting. 

What causes Factor IX Deficiency?

Factor IX Deficiency is caused by a change, or mutation, in the F9 gene.  This mutation causes the gene to not work properly or not work at all.  Normal function of the F9 gene is important for making Factor IX, a protein that helps in blood clotting.  When the F9 gene in a male does not work correctly, it leads to the symptoms described above. 

Factor XI Deficiency

  • Horizon 106
  • Horizon 274

What is Factor XI Deficiency?

Factor XI Deficiency, also called Hemophilia C, is an autosomal recessive bleeding disorder that causes mild to heavy bleeding, especially following dental tooth extraction, surgery, or trauma.  Some people with Factor XI Deficiency also experience frequent nosebleeds and bruising.  Women may have heavy menstrual cycles or postpartum bleeding.  Most people with this condition will have mild symptoms; however, symptoms may be more severe in certain cases. Treatment with medications that help blood clot more quickly may be helpful for people with severe bleeding problems.  Factor XI deficiency is considered less severe than other forms of hemophilia (types A and B). 

What causes Factor XI Deficiency?

Factor XI Deficiency is caused by a gene change, or mutation, in both copies of the F11 gene pair. These mutations cause the genes to not work properly or not work at all. Normal function of the F11 gene pair is important for making a protein that helps in blood clotting. When both copies of the F11 gene do not work correctly, it leads to the symptoms described above.  When one copy of this gene works correctly and the other does not, it may cause mild bleeding problems or no symptoms at all. 

Familial Dysautonomia

  • Horizon 14
  • Horizon 27
  • Horizon 106
  • Horizon 274

What is Familial Dysautonomia?

Familial Dysautonomia is an autosomal recessive disorder that affects the nervous system. Symptoms usually start in infancy and include poor muscle tone (hypotonia), problems with feeding and digestion, episodes of vomiting, lessened sensitivity to pain, and problems keeping a normal body temperature. Children with Familial Dysautonomia may also have delays in reaching developmental milestones, such as walking.  Currently there is no cure for this disorder and treatment is based on symptoms.

What causes Familial Dysautonomia?

Familial Dysautonomia is caused by a gene change, or mutation, in both copies of the IKBKAP gene pair.  These mutations cause the genes to not work properly or not work at all.   When both copies of this gene do not work correctly, it leads to the symptoms described above. 

Familial Hypercholesterolemia, LDLR-Related

  • Horizon 106
  • Horizon 274

What is Familial Hypercholesterolemia, LDLR-Related?

Familial Hypercholesterolemia, LDLR-Related is an autosomal dominant inherited disorder that causes high cholesterol levels in the body. Cholesterol is a waxy, fat-like substance that is found in all cells of the body. With Familial Hypercholesterolemia, LDLR-Related, the body is unable to remove LDL (low density lipoprotein, also known as "bad" cholesterol) from the blood. High blood levels of LDL cholesterol can lead to heart disease in adulthood and other symptoms including fatty skin deposits (xanthomas) over parts of the hands, elbows, knees, ankles, and around the cornea of the eye; cholesterol deposits in the eyelids (xanthelasmas); chest pain (angina) or other signs of coronary artery disease; sores on the toes that do not heal; and sudden stroke-like symptoms.  About 1 in 500 people has Familial Hypercholesterolemia, LDLR-Related.

When both parents have Familial Hypercholesterolemia, LDLR-Related, their children can inherit a more severe childhood-onset form of the condition called Homozygous Familial Hypercholesterolemia, LDLR-Related.  In these cases there is a much greater increase in blood cholesterol levels resulting in a high risk for heart disease and heart attacks in childhood.

What causes Familial Hypercholesterolemia, LDLR-Related?

Most cases of high cholesterol are due to a combination of genetic and lifestyle factors.  There are several inherited (familial) forms of hypercholesterolemia caused by gene changes (mutations) in different genes, most commonly the LDLR gene.  When Familial Hypercholesterolemia is caused by a mutation in the LDLR gene, it is called Familial Hypercholesterolemia, LDLR-Related.

Familial Hypercholesterolemia, LDLR-Related is caused by mutations in the LDLR gene and has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means having a change, or mutation, in one copy of a pair of genes is enough to cause the disorder.  The mutation causes the gene to not work properly or not work at all. Normal function of the LDLR gene is important in helping the body get rid of excess LDL cholesterol from the blood.   When one copy of the LDLR gene is not working properly, it causes the symptoms of Familial Hypercholesterolemia, LDLR-Related described above. 

Rarely, a child can inherit mutations in both copies of the LDLR gene pair. This happens when both parents have Familial Hypercholesterolemia, LDLR-Related (one LDLR gene mutation) and each passes their LDLR gene mutation to their child.  Children who inherit mutations in both copies of their LDLR genes have severe childhood-onset Homozygous Familial Hypercholesterolemia, LDLR-Related with symptoms that start at much younger ages than those with only one LDLR gene mutation. 

Familial Hypercholesterolemia, LDLRAP1-Related

  • Horizon 274

What is Familial Hypercholesterolemia, LDLRAP1-Related?

Familial Hypercholesterolemia, LDLRAP1-Related is an autosomal recessive disorder that causes very high levels of cholesterol in the blood. Cholesterol is a waxy, fat-like substance that is found in all cells of the body.  Too much cholesterol in the blood increases the risk of heart disease. With Familial Hypercholesterolemia, LDLRAP1-Related the body is unable to remove LDL (low density lipoprotein, also known as ‘bad’ cholesterol) from the blood.  High blood levels of LDL cholesterol can lead to heart disease in early adulthood.  Other symptoms include fatty skin deposits (xanthomas) over parts of the hands, elbows, knees, ankles, and around the cornea of the eye; cholesterol deposits in the eyelids (xanthelasmas); chest pain (angina) or other signs of coronary artery disease; sores on the toes that do not heal; and sudden stroke-like symptoms. Treatment usually includes a medical low-cholesterol, low-fat diet along with cholesterol lowering medication and other supplements as indicated.

What causes Familial Hypercholesterolemia- LDLRAP1-Related?

Familial Hypercholesterolemia, LDLRAP1-Related is caused by a gene change, or mutation, in both copies of the LDLRAP1 gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it causes the symptoms described above.

Back to Top